Handle break as continue

pkg/compiler/lib/src/ssa/builder_kernel.dart

Index: pkg/compiler/lib/src/ssa/builder_kernel.dart
diff --git a/pkg/compiler/lib/src/ssa/builder_kernel.dart b/pkg/compiler/lib/src/ssa/builder_kernel.dart
index a924a681ca2111a170502ec701844acf55468748..108248ce9ff6f1b9860899edac18fa93d65217d9 100644
--- a/pkg/compiler/lib/src/ssa/builder_kernel.dart
+++ b/pkg/compiler/lib/src/ssa/builder_kernel.dart
@@ -901,11 +901,12 @@ class KernelSsaGraphBuilder extends ir.Visitor
       forStatement.body.accept(this);
     }
 
+    JumpTarget jumpTarget = localsMap.getJumpTargetForFor(forStatement);
     loopHandler.handleLoop(
         forStatement,
         localsMap.getClosureRepresentationInfoForLoop(
             closureDataLookup, forStatement),
-        localsMap.getJumpTargetForFor(forStatement),
+        jumpTarget,
         buildInitializer,
         buildCondition,
         buildUpdate,
@@ -1466,10 +1467,18 @@ class KernelSsaGraphBuilder extends ir.Visitor
     assert(target != null);
     JumpHandler handler = jumpTargets[target];
     assert(handler != null);
-    if (handler.labels.isNotEmpty) {
-      handler.generateBreak(handler.labels.first);
+    if (localsMap.generateContinueForBreak(breakStatement)) {
+      if (handler.labels.isNotEmpty) {
+        handler.generateContinue(handler.labels.first);

[Siggi Cherem (dart-lang), 2017/06/23 21:03:59]

is this label in the right place?

or do we need to move it? ( `for (;;) l1: { ... }`  => `l1: for(;;) { ... } `)

[Johnni Winther, 2017/06/26 11:27:56]

It's the responsibility of the jump target (here the for-statement). Currently
labels are not supported.

+      } else {
+        handler.generateContinue();
+      }
     } else {
-      handler.generateBreak();
+      if (handler.labels.isNotEmpty) {
+        handler.generateBreak(handler.labels.first);
+      } else {
+        handler.generateBreak();
+      }
     }
   }
 
@@ -1485,8 +1494,14 @@ class KernelSsaGraphBuilder extends ir.Visitor
       body.accept(this);
       return;
     }
-    JumpHandler handler = createJumpHandler(
-        labeledStatement, localsMap.getJumpTargetForLabel(labeledStatement));
+    JumpTarget jumpTarget = localsMap.getJumpTargetForLabel(labeledStatement);

[Siggi Cherem (dart-lang), 2017/06/23 21:03:59]

I thought eventually the visitor was going to generate jump targets eagerly for
all labeled statements, is that not the case?

[Johnni Winther, 2017/06/26 11:27:56]

No, only for those that _are_ targets. An untargetted label statement is
replaced by its body (as they are in ssa/builder)

+    if (jumpTarget == null) {
+      // The label is not needed.
+      body.accept(this);
+      return;
+    }
+
+    JumpHandler handler = createJumpHandler(labeledStatement, jumpTarget);
 
     LocalsHandler beforeLocals = new LocalsHandler.from(localsHandler);